1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for optimizing execution of Input/Output (‘I/O’) requests for a disk drive in a computing system.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
One of the areas in which progress has been made is in optimizing execution of I/O requests for a disk drive in a computing system. A disk drive device driver or a disk drive controller often has many I/O requests to process at any given moment. Each of the I/O requests specifies one or more physical disk blocks of the disk drive to access. Due to seek time, settle time, and rotational latency present when executing any I/O request, accessing disk blocks of a particular I/O request in the order in which that I/O request specifies the disk blocks is typically not efficient. Similarly, processing the I/O requests in the order in which the requests were received from the operating system is also typically not efficient.